A periodontal disease is often referred as Pungchi, and it means an inflammatory disease accompanying destruction of periodontal tissues caused by bacterial complex infection (mixed infection). It shows various clinical symptoms such as gingival bleeding and swelling, formation of periodontal pocket, loss of attached gingival, destruct ion of alveolar bone, and bad breath, and it is becoming a major cause of tooth loss and implant failure.
Such periodontal disease is a very different disease in aspects of oral tissues occurred, causative organisms, and onset mechanism, compared to dental caries which is generally called cavity. Specifically, dental caries occurs on tooth, and a periodontal disease occurs in periodontal tissues (cement, gingival, periodontal ligament, alveolar bone). The causative organisms of dental caries are bacterial species expressing organic acids (mainly lactic acid) by carbohydrate fermentation metabolism including mutans group streptococcus, while a periodontal disease mainly occurs by gram negative anaerobic bacteria. In other words, dental caries is occurred in an acidic condition, whereas a periodontal disease is occurred in a basic condition. That is because nitrogen metabolism occurs more actively than carbohydrate metabolism in gram negative anaerobic bacteria. Thereby, tartar is built a lot in the region where a periodontal disease occurs.
Such periodontal disease is known to generally occur by various topical and systemic factors, and the most important one of topical factors is a dental plaque, which is known as up to now about 500 bacterial species exist in the dental plaque and they form a kind of biofilm. Among such bacterial species, major causative organisms of periodontal diseases include Fusobacterium nucleatum, and Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra (also called Peptostreptococcus micros), and Aggregatibacter actinomycetemcomitans (also called Actinobacillus actinomycetemcomitans), etc.
An innate immune response and destruction mechanism of alveolar bone by such pathogenic bacteria of periodontal diseases are as follows.
Human gingival epithelial cells primarily act as physical barriers to prevent bacterial invasion, and secret anti-bacterial peptides (human beta defensins and LL-37 etc.). Thus, as a result of susceptibility investigation to anti-bacterial peptides secreted from human gingival epithelia, defensins and LL-37, it is reported that strongly pathogenic bacterial species (P. gingivalis and P. intermedia) are highly susceptible to the anti-bacterial peptides, while low pathogenic bacterial species (S. mutans etc.) and F. nucleatum are killed at a low concentration.
In addition, human gingival epithelial cells secret cytokines and chemokines like Interleukin-8(IL-8) and IL-1α, etc. by causative organisms of periodontal diseases, thereby inducing innate immune responses and removing those bacteria. If a primary barrier, gingival epithelial cells are destroyed by oral microorganisms in a dental plaque, adaptive immune responses as well as innate immune responses are activated, and in case of not removing pathogens, destruction of periodontal tissues is accelerated.
Also, the continuity of gingival epithelia is protected by neutrophils and antibodies from bacterial infection. Specifically, bacterial toxins are neutralized by antibodies and bacteria become opsonized (opsonization) by complement activity, thereby bacteria are removed by macrophages. However, when the continuity of gingival epithelial cells is destroyed, bacteria or bacterial products [LPS, phosphoryl choline, proteasleukotoxin, cytolethal distendingtoxin(CDT), etc.] are introduced in periodontal tissues, thereby inducing immune responses, and immune mediated molecules such as interleukin(IL)-1, IL-6, prostaglandinE2(PGE2) and tumor necrosis factor(TNF)-α, etc. are secreted by lymphocytes, macrophages, etc., and a receptor activator of nuclearfactor κB ligand(RANKL) osteoprotegerin(OPG) is secreted in gingival epithelial cells, periodontal ligament epithelial cells, preosteoblast, etc., thereby controlling differentiation of osteoclasts. Then, human periodontal ligament fibroblasts increases RANKL expression, reduces OPG expression by responding to IL-1, and promotes differentiation of preosteoclasts, thereby participating in destruction of alveolar bone.
On the other hand, gingival fibroblasts promote OPG expression by responding to IL-1, thereby inhibiting differentiation of preosteoclasts.
Meanwhile, LPS of A. actinomycetemcomitans combines to TLR-4 of periodontal ligament cells, activates p38 MARK pathway, and increases differentiation of preosteoclasts. P. gingivalis increases RANKL expression from periodontal ligament cells by Lys-gingipain.
However, even though periodontal diseases are occurred by mixed infection of various bacterial species, mostly only researches for innate immunity to single bacterial species are progressed.
Currently, the treatment of periodontal disease includes oral hygiene improvement of patients, non-surgical treatment and surgical treatment (dental plaque removal, root planning, gingival curettage, regeneration of periodontal tissues applied with new attachment). The most effective treatment, surgical treatment has inconvenience to go to the dentist for treatment and limitation of performing when a disease progresses in some degree rather than prevention of the disease. Therefore, as periodontal diseases are not effectively treated, periodontal diseases mostly become chronic. As additional treatments, systemic administration of antibiotics and local sustained release formulations have been used, but there are serious problems, as there have been reported side effects caused by delivering too many agents to unneeded regions and a case in which a periodontal disease bacterium is separated, which shows resistance to antibiotics.
In particular, in case of our country, according to “2013 Health Statistics Index” by Health Insurance Review & Assessment Service, the number of people who visited dentistry due to periodontal diseases increased by more than 10 million people, about twice that of 2004. Although a periodontal disease is a disease which people in our country are suffering except acute upper respiratory inflammation (common cold), there have been reported that drugs such as Igatan® and Insadol®, etc., which are currently known as representative therapeutic agents for periodontal diseases, actually do not have direct effects on periodontal diseases and are merely health food or supplements.
Researches have been carried out to investigate an antibacterial activity using natural plant extracts to develop alternative substances for complementing limitation of surgical treatments and problems of antibiotics use and enhancing effects of preventing and treating periodontal diseases
For example, substances having antibacterial activities have been developed by measuring antibacterial activities to causative bacteria for periodontal diseases in nature extracts such as red ginger roots (Park et al., Phytother. Res. 22, 1446-1449, 2008), medicinal plants of South Africa, lotus leaves (Li and Xu, Arch. Pharm. Res. Vol 31, No. 5, 640-644, 2008), etc., and recently, it is demonstrated that as treating GCSB-5, after injecting a substance isolated from licorice extracts with inflammatory substances iNOS and COX-2 to a lipopolysaccharide (LPS), which is an endotoxin substance existing in cell walls of A. actinomycetemcomitans and P. gingivalis, activation of intracellular messengers (Akt and NF-kB) which participate in inflammatory process reduces, thereby alleviating symptoms and edemas (Bodet et al., J. Periodontol. Vol. 9, No. 9, 2008). However, a therapeutic agent derived from nature plants or health functional foods which are effective against periodontal diseases are not commercially available so far.
Meanwhile, mangosteen (Garcinia mangostana) is a fruit of a dicotyledonous plant belonging to Sapindales pepper tree of origin of Malaysia and bear a slightly larger size of fruit than a flat ball-shaped table tennis ball. The fruit of mangosteen is known to have excellent antioxidant ability, since it contains a representative antioxidant component called xanthone, which is a kind of polyphenols. In the Southeast Asia including Thailand, it has been used as a folk drug a long time age, for treating inflammation or injuries like wounds, etc.
Further, as other uses of mangosteen, with respect to mangosteen pericarps, food preservatives in Japanese laid-open patent application No. 6-98738 and laid-open patent application No. 7-147951, 5α-reductase in laid-open patent application No. 5-17365, antibacterial agents in laid-open patent application No. 7-250658, anti-helicobacter pylori drugs in laid-open patent application No. 8-208501, ultraviolet absorbers in laid-open patent application No. 9-87155, and serine protease inhibitors in laid-open patent application No. 10-120586 are disclosed.
Also, with respect to water-soluble extracts of manhosteen pericarps, whitening and anti-inflammatory actions by inhibitory action of histamine isolation from mast cells are disclosed in Japanese laid-open patent application No. 4-244004. With respect to polar solvent extracts of mangosteen pericarps and alpha-mangosteen, gamma-mangosteen, anti-allergic actions by antagonism for histamine and serotonin are disclosed in Japanese laid-open patent application No. 10-72357. However, an effect regarding periodontal diseases of mangosteen extracts and substances isolated from thereof is not disclosed at all.
Under these backgrounds, the present inventors have intensively researched to develop pharmaceutical and food compositions having excellent effects on preventing, improving and treating periodontal diseases based on natural products. As a result, it is demonstrated that mangosteen extracts and alpha-mangosteen, gamma-mangosteen isolated from thereof have substantially excel lent antibacterial and anti-inflammatory effects against causative organisms for periodontal diseases, thereby completing the present invention.